Medical events are among the most common traumatic experiences for American children: each year, nearly 9 million receive emergency care for injury, more than 10,000 receive a new cancer diagnosis or undergo organ transplantation, and many more experience disruptive and painful medical events. While many youth recover well, a significant subset experience persistent psychological symptoms (e.g., posttraumatic stress [PTS] reactions) and impaired health-related quality of life (HRQOL). Resources for psychosocial support are limited, making innovative delivery of effective interventions essential. The Internet provides a promising, accessible means to reach a wide range of children and families. We have developed an innovative child-focused web intervention, grounded in the evidence base regarding etiology of post-trauma psychological reactions, and guided by a strong conceptual framework. Via interactive game-like activities, Coping Coach targets appraisals and coping (e.g., avoidance, support-seeking) to promote healthy adaptation and recovery. Aims: 1) Assess and maximize intervention feasibility, 2) Conduct initial efficacy testing (pilot RCT) for proximal outcomes (appraisals, coping) and subsequent child health outcomes (PTS reactions, HRQOL), 3) Refine conceptual framework and optimize intervention effectiveness; prepare for rigorous large-scale RCT. Method 1) Expert review: Experts will review Coping Coach for congruence with the conceptual framework and targets. 2) Evaluate feasibility: 10 children (ages 8-12), hospitalized for a recent acute medical event, will utilize Coping Coach. Observations and feedback (6 week follow-up) will assess acceptability, engagement, and barriers. 3) Refine intervention: We will modify Coping Coach as needed, based on expert review and feasibility testing. 4) Assess efficacy in pilot randomized trial: 70 children (same criteria) will complete baseline measures, and then be randomized to Coping Coach or usual care. Baseline assessments and blinded follow-ups (at 6 and 12 weeks) will assess appraisals, coping, HRQOL, and psychological reactions. 5) Determine need for further refinement of intervention and conceptual framework: Based on pilot RCT results, plan modifications and prepare Coping Coach for further testing. Importance By exploring mechanisms of action and estimating initial efficacy, this project lays the groundwork for more rigorous evaluation of Coping Coach, and informs underlying theory regarding children's emotional and psychological recovery. Our translational research program develops innovative, theoretically-grounded secondary prevention tools to improve health outcomes in children, advancing NICHD's goal to improve health and well-being of families and Healthy People 2020 goals to promote high-quality, health-related Web sites and the delivery of evidence-based clinical preventive services.